Gina, I swear to you the only thing I have ever used in a toilet bowl
is, ready for this? COMET! Yep, plain comet. I have never had a stain
in all the years I have cleaned a bowl! It is sparkling and shinny.
The cleanser lightly scrubs the inside and the bleach keeps it from staining.
It may take you a couple times in doing it since yours is discoloring but
sprinkle Comet in and leave it there for about an hour before flushing.
Do it again in a couple of days. If you have more than one bathroom leave
it in overnight. In 48yrs I have not used anything else.
I have tried those deordorizers you put in the back of the tank that is
suppose to clean the bowl. All they do is turn into scum in the tank! YUK.
Comet does the trick for me.